The metabolism, distribution and elimination of chlorphentermine in man.

1 A gas-liquid chromatography procedure for the determination of chlorphentermine (I), N-hydroxychlorphentermine (II) and alpha,alpha-dimethyl-alpha-nitro-beta-(4-chlorophenyl)ethane (IV) in urine has been developed. Also methods are reported to determine conjugated II and the total N-oxidized metabolites of I, i.e. II, conjugated II, alpha,alpha-dimethyl-alpha-nitroso-beta-(4-chlorophenyl)ethane (III) and IV in urine. 2 The synthesis of alpha,alpha-dimethyl-alpha-nitroso-beta-(4-chlorophenyl)ethane (III) and its properties are reported. 3 The kinetics of urinary excretion of I and its metabolic products after the oral administration of I to a human subject on separate occasions have been studied. Under normal conditions of urinary pH, metabolism by N-oxidation was the main elimination route of I; acidifying the urine increased the urinary excretion of unchanged I at the expense of the N-oxidized products. 4 The importance of the N-oxidation metabolic route in the distribution of chlorphentermine (I) in man is discussed.